SIMULTANEOUS LIQUID-CHROMATOGRAPHIC DETERMINATION OF CENTCHROMAN AND ITS 7-DEMETHYLATED METABOLITE IN SERUM AND MILK

A precise and sensitive high-performance liquid chromatographic assay was developed and validated for determination of centchroman (I) and i ts 7-demethylated metabolite (II) in human serum and milk. The serum, at alkaline pH, was extracted with diethyl ether. In the case of milk, after precipitation of the milk protein with acetonitrile, the supern atant was evaporated to dryness and then extracted with diethyl ether at alkaline pH. After solvent evaporation the residue was reconstitute d in mobile phase. Separations were accomplished by reversed-phase liq uid chromatography using a Spheri-5 cyano column. Recoveries of I and II were always >95%. Excellent linear relationships (r>0.999) were obt ained between the measured and added concentration ratios of the corre sponding serum and milk concentrations over a range of 1 to 1000 ng/ml and 2.5 to 1000 ng/ml for I and II, respectively.